Multiple effect hoist system



Oct. 12, 1965 3,211,428

LE ROY D. SPRACKLIN MULTIPLE EFFECT HOIST SYSTEM Filed March 5, 1964 INVENTOR. Leroy D.Sprocklin United States Patent 3,211,428 MULTIPLE EFFECT HOIST SYSTEM Le Roy D. Spracklin, Box 51, Jordan, Mont. Filed Mar. 5, 1964, Ser. No. 349,661 4 Claims. (Cl. 254-93) This is a continuation-in-part application, of my earlier filed application, Serial No. 302,624, filed August 16, 1963, for Multiple Effect Hoist System, and now abandoned.

This invention relates to hoist mechanisms, and, more particularly, to a hydraulically actuated hoist system.

It is an object of the present invention to provide a double acting, hydraulic hoist mechanism in which leverage is applied to diametrically opposite sides of circular drive discs from the opposite ends of a hydraulic ram and cylinder assembly, to thus improve operating efficiency and total leverage action.

A further object of the present invention is to provide a multiple effect hoist system of the type described in which horizontal stability of the hydraulic cylinder is maintained and controlled by pendulum type rod arms which suspend the hydraulic cylinder from a fixed part of the frames, and automatic link journal connections are made between the outer ends of the cylinder and ram and diametrically opposite sides of circular drive plates for effecting a rotational movement to articulated linkage of a hoist mechanism.

All of the foregoing and still further objects and advantages of this invention will become apparent from a study of the following specification, taken in connection with the accompanying drawing, wherein:

FIGURE 1 is a side elevational view, with parts broken away, of a multiple effect hoist system made in accordance with the present invention in an initial deactivated condition;

FIGURE 2 is a view similar to FIGURE 1, showing the parts of the mechanism in an extended position; and

FIGURE 3 is an enlarged fragmentary top plan view with parts broken away, of the assem'bly shown in FIG- URE 2.

Referring now to the drawing, a multiple effect hoist system made in accordance with the present invention, is shown to include a cross shaft 12 which is splined at each end to receive a pair of spacers 11 with matched splines for engagement with the splines of the cross shaft. One end of a pair of lift arms 14 is secured, such as by welding, to each spacer 11, to thus rotate with the shaft 12. A nut 17 secures each spacer and lift arm unit upon the respective end of the shaft 12. The outer end of each such lift arm 14 is pivotally connected by means of pivot pins 18 to one end of articulated links 16 having means at their opposite ends for connection to the object to which a force is to be transmitted, such as the lift body of the vehicle. The shaft 12 may thus be mounted by means of bearings 19 upon the underframe 13 of the vehicle.

A pair of circular drive plates 20 are mounted upon the cross shaft 12, inboard of the lift arms 14, and are maintained in a spaced apart parallel relationship and integrally connected by means of a spacer member 22. The spacer member 22 is keyed or connected by splines 23 to the cross shaft 12, so as to rotate with the cross shaft and lift arms 14. The inboard side of each drive plate 20 is provided with a pair of diametrically spaced apart journal pry rests 24, for purposes hereinafter more fully described.

The power system includes a hydraulic cylinder 26 having an outermost end 32 horizontally stabilized by means of a pair of pendulum rod arms 28 pivotally connected at one end to a fixed part of the structure, such as the frame of the vehicle, and the opposite ends pivotally connected by means of pivot pins 30 to the cylinder base 32. This base 32 is also provided with pivot pins 34 for pivotally connecting one end of a pair of tension rods 36 which are pivotally connected at their opposite ends by means of a connecting pin 38 carried by one end of a pair of links 40. Each of these links 40 is pivotally connected at its opposite ends to a peripheral portion of each circular drive plate 20 by means of a pivot pin 41. Another pair of links 40 is mounted by means of a pivot pin 42 to a diametrically opposite side of the drive plates 20 from the first pair of links 40. The outer ends of the second pair of links' are pivotally connected by means of a pivot pin 43 to the outermost end of the ram rod 44 of the piston 46 of the cylinder 26.

It must be recognized that with the mechanism in the initial position shown in FIGURE 1, the supply of hydraulic fluid to the cylinder 26 will cause extension of the piston 46 and rod 44, whereby the rod 44 will exert a pushing action upon its connecting link pin 43 and its links 40 to bear against their respective pry rests 24 to rotate the drive plates 20; and the tension rods 36 will simultaneously effect a pulling action upon the pin 38 to bring the associated pair of connecting links 40 to bear upon their respective pry rests 24, to rotate the drive plates 20 as the rear end of the cylinder 26 is simultaneously retracted as the rod 44 is extended. Thus, the double action of the cylinder and ram rod effects a limited rotation of the drive discs or plates 20 which rotate the cross shaft 12 and the articular lift arms 14, 16 secured thereupon, toward the extended position shown in FIGURE 2. During such actuation, the connecting links 40 disengage from bearing relationship with their pry rests toward the latter part of the stroke of the piston, as shown in FIGURE 2. Also, during such actuation, the pendulum rod arms 28 stabilize the free end of the cylinder and accommodate its displacement during actuation of the cylinder.

It will thus be appreciated that a major feature of this invention is the multiplication and balancing of the efiects of hydraulic forces by means of application of said hydraulic forces to two diametrically space-d opposite sides of the drive plates 20.

It will also be appreciated that another major feature of this invention is the further automatic and continuous multiplication of the effects of these previously multiplied hydraulic forces, by means of the automatic high torque and variable link journal consisting of parts 38, 40, 41, 42 and 43, combined in the transmission of said forces to the drive plates 20.

The unit is also extremely compact in reference to the minimum amount of operating space required for actuation of the parts and extension of the articulated linkage. The systemmay be readily disassembled and the size of the parts adjusted to provide maximum flexibility of installation and adaptation to various job or load requirements.

Thus, the major feature advantages of this invention, in addition to flexibility, stability and variability, shall provide substantially greater leverage advantages in the final positioning of the unit relative to the load for any desired purpose.

While this invention has been described with particular reference to the construction shown in the drawing, it is to be understood that such is not to be construed as imparting limitations upon the invention, which is best defined by the claims appended hereto.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A multiple effect hoist system comprising, in combination, a hydraulic cylinder having a base and a ram rod, a cross shaft, means for mounting said cross shaft directly upon a rigid support for rotation of said cross shaft, an articulated lift arm, fixedly secured at one end upon said cross shaft for rotation therewith, a pair of drive plates fixedly secured in spaced apart relationship upon said cross shaft intermediate the ends thereof, mechanical advantage means supporting said base and operatively connected between said base and ram rod of said hydraulic cylinder and said drive plates to rotate said cross shaft and said articulated lift arm, and means for operatively connecting said lift arm to a member for hoisting thereof.

2. A multiple effect hoist system as set forth in claim 1, wherein said mechanical advantage means comprises pairs of links, one pair of said links being pivotally connected at one end to first juxtaposed port-ions of said drive plates, another pair of said links being pivotally connected at one end of each link to second juxtaposed portions of said drive plates diametrically opposite to said first juxtaposed portions, said ram rod being pivotally connected at the opposite end of said one pair of links, and tension rods pivotally connected at one end of each to said base of the cylinder and pivotally connected at the opposite end of each to the opposite ends of said another pair of links.

3. A multiple effect hoist system as set forth in claim 2, further comprising pry rests carried upon the facing sides of said drive plates, one of said pry rests being adjacent each of said links, and both of said pairs of links acting against said pry rests during initial actuation of said cylinder.

4. A multiple effect hoist system as set forth in claim 3, characterized in that said means for supporting said cross shaft comprises bearing means and said mechanical advantage means includes self adjusting hanger means supporting said cylinder for movement within a plane extending normal to said cross shaft.

References Cited by the Examiner UNITED STATES PATENTS 2,581,662 1/52 Hutchinson. 2,620,225 12/52 Hutchinson. 2,836,460 5/58 Lundell.

WILLIAM FELDMAN, Primary Examiner.

MILTON S. MEHR, Examiner. 

1. A MULTIPLE EFFECT HOIST SYSTEM COMPRISING, IN COMBINATION, A HYDRAULIC CYLINDER HAVING A BASE AND A RAM ROD, A CROSS SHAFT, MEANS FOR MOUNTING SAID CROSS SHAFT DIRECTLY UPON A RIGID SUPPORT FOR ROTATION OF SAID CROSS SHAFT, AN ARTICULATED LIFT ARM, FIXEDLY SECURED AT ONE END UPON SAID CROSS SHAFT FOR ROTATION THEREWITH, A PAIR OF DRIVE PLATES FIXEDLY SECURED IN SPACED APART RELATIONSHIP UPON SAID CROSS SHAFT INTERMEDIATE THE ENDS THEREOF, MECHANICAL ADVANTAGE MEANS SUPPORTING SAID BASE AND OPERATIVELY CONNECTED BETWEEN SAID BASE AND RAM ROD OF SAID HYDRAULIC CYLINDER AND SAID DRIVE PLATES TO ROTATE SAID CROSS SHAFT AND SAID ARTICULATED LIFT ARM, AND MEANS FOR OPERATIVELY CONNECTING SAID LIFT ARM TO A MEMBER FOR HOISTING THEREOF. 